Sound amplifier



March 24, 1931. c N

SOUND AMPLIFI ER Filed Dec. 15, 1920 Patented Mar. 24, 1931 PATENTOFFICE CHESTER ALFRED LINTON, OF KANSAS CITY, MISSOURI SOUND AMPLIFIERApplication filed December 13, 1920.

This application is a modification of an earlier co-pending applicationfor patent filed by me November 16, 1920, Serial No. 424,847, in which Ishow various modified 6 forms each capable of many variations andmodifications in structure while remaining within the spirit of myinvention.

My invention relates to sound amplifiers and the like and particularlyto means for improving the quality of sounds passing through soundamplifiers and the like having resonant Walls or parts.

My invention concerns a novel means of focusing sounds at certaindesired points on an acoustical apparatus by and through elastic orresonant means that may be solid or substantially solid.

It is particularly adapted for use in connection with the sound-box of atalking machine recorder or reproducer, but my invention is not limitedto such type of device or machine but may be applied to other forms.

I have discovered that by outwardly connecting resonant bars or membersor sound conducting members to different portions of a resonantamplifier or acoustical apparatus in such manner that longitudinally thebodies of the resonant bars or members or sound conducting members willbe largely free from interference of the air vibrations inside thetubular passage of the amplifier or, acoustical apparatus, the soundspassing through a resonant sound amplifier or acoustical apparatus mayberegulated prac tically as desired. In my co-pending application referredto above, I show resonant bars or members or sound conducting membersconnected in an elevated manner to differ ent portions of a soundamplifier or acoustical apparatus having a straight passage for sound,and by their use the quality and brilliancy of sounds were greatlyimproved.

I have further discovered that by connecting resonant bars or members orsound conducting members by one of their respective ends topredetermined places on a tubular throat portion of a sound amplifier orsound recorder and by connecting the other of their respective ends to asupplemental or cooperative amplifying or resonator member,

Serial No. 430,209.

sounds passing through a tubular throat portion of a. sound amplifier orsound recorder well be clarified with great facility and the distortionof sound caused by the curvature of a threat portions walls will belessened. I have discovered that sounds may thus be transmitted to orfrom a supplemental or cooperative member and, also, that suchtransmitted sounds help reinforce other sounds issuing from out anorifice of a tubular throat portion of a sound amplifier or soundrecorder and thus provide a more life-like effect of sound coming from alarge instrument like a piano or from a group of players.

One object of my present invention is to provide a novel compactarrangement of sound conducting members on an amplifier for sounds.

Another object of my invention is to provide novel improvements in asound amplifier, by means of which sounds will be diffused.

Another object of my invention is to provide a supplemental orco-operative amplifymg or resonator member or the like connected to asurface of an acoustical apparatus by suitable means that may be solidor substantially solid so that sounds may be recorded with greaterfacility and ease and many overtones that would otherwise be lost may berecorded on a suitable record.

Another object of this invention is to provide means for transmittingsounds to or from a sound amplifier or acoustical apparatus to or from aco-operative member whereby the sounds will not be distorted as theywould he were they transmitted by' purely air means.

Further objects of this invention are to provide means to help regulatethe pitch of sounds that may be transmitted; to provide means forobtaining resultant tones; to provide a novel plurality of resonators;to provide an improved sound apparatus which will be of durableconstruction; and to provide other improvements as hereinafter set forthin the following specification and accompanying drawings, consideredtogether or separately.

In the accompanying drawings,

Fig. 1 is a side elevation of a sound amphfier, showing substantiallysolid sound con ducting members or bars or members and showing adiaphragm or a supplemental or co-operative member above or adjacent.

Fig. 2 is a top view of the same, showing angular bars or members orsound conducting members.

Fig.3 is a front elevation of Fig. 1, showing curved walls of tworesonators.

F ig. l is a cross section on the line 1-4 of Fig. 2, showing a circularthroat formation and showing web attachments of solid or substantiallysolid bars or members or sound conducting members. I

To illustrate this modification of my invention, I annex hereto onesheet of drawings. in which similar reference characters are used todesignate similar parts in the difierent views.

Numerous ideas have been carried out in this invention, with recognitionon my part that one or more novel elements or combinations, etc., can beemployed separately. One discovery portrayed in the invention is that anelement has certain latent potential vibratory or acoustic capabilities,and, furthermore, that when this idea is combined with structure havingseveral elements,-say a plurality,-the latent yet workable potentialacoustic or vibratory capabilities are adapted for causal purposes orfinite control, with most any useful result novel by any of these orlike means, and either with minimum or maximum structure, possible. Thepoint of the application of force is not always terial, as will becomeclear in this specification. Factors of stress are known herein relativewith what is made apparent and of simple application when following theintent of the description. The steps taken in the relationship of valuesof, or the comparative ratios of, elasticity, density, inertia, etc, ofmasses will be found of essence in understanding the interrelation orinterdependence of acoustic factors, altho an expert in the art shouldunderstand the revolutionary nature of the invention that makes use ofthe discovery of the relativity of acoustic factors for the productionof a. new result, or new results. The invention is foreseen as alterableand adapted for mutation, on a lar 'e scale. Therefore, when viewedbroadly, the drawing clearly shows relevant phenomena in a diaphragm,plate, or rod, or sliver, etc, may be computed; and this marks adifferen'ce between this invention and the prior art.

In the drawings which illustrate my improvements as applied to a soundamplifier or the like, 1 designates the tubular resonator or bellportion and 2 the tubular throat portion of the amplifier, or the like.'These said portions are preferably of wood and, to provide anuninterrupted passage for sound, are, preferably, connected to adjacentends, preferably by gluing or cementing. The amplememes tier may, ifdesired, be suitably curved and of flaring or tapering form.

Inner surfaces of the tubular throat portion 2 and the tubular bellportion 1 are in this instance provided with a hard coating, such asasphaltum or the like, this coating being, preferably, pumicated orsanded or roughened or the like to remove the glazed surface. This hardsurface, thus treated, effects the best results. If desired the hardcoa-ing, such as asphaltnm or the like, may be placed upon one or morecoatings of varnish on the inner surfaces of the sound amplifier, or onthe inner surfaces of the portions 1 and 2, and, also, if desired, uponone or more coatingsof varnish on the outer and rear sides of thetubular throat portion 2. Good results are attained without any coat ingin onstruction, therefore coating material of any kind may be dispensedwith if preferred.

For increasing the purity of the sound waves and for adding newfrequencies over tone effects 1 provide at opposite sides of the soundamplifier a number of sound conducting members or resonant bars, eachplurality of which may consist of an inner body 8 and an outer body l.The ends of the bodies 3 and 4: are in this instance respectivelyconnected, preferably by gluing or cenien 'ng, to the outside of thewalls of the bell portion 1 and the tubular throat portion 2, as shownin Fig. 2.

In the arrangement selected for illustration, the bodies 3 and a of eachplurality of sound conducting membersv or resonant bars are ofsubstantial area in cross section and preferably of determined frequencyand are connected to each other by a relatively thin resilientlongitudinal web ormembrane or the like 5, as shown in the crosssectional view in l. Each body 3 is suitably con nected by the edges ofa relatively thin resilient longitudinal web 6 to the outside of thewalls of the said sortions 1 and 2v of the sound amplifier or recorder.The preferred arrangement of the web or membrane or the like? is shownin the cross sectional view in l selected for illustration of theprinciple employed. These webs may, if desired, be on ved and in thesame plane or curved longitudinally or horizontally or in any positionin keeping within the broad scope of this invention.

For conducting sound vibrations from the tubular throat portion 2 to thetubular bell portion 1, there is also preferably pro-' videda soundconducting member or resonant bar or member comprising a substantialbody portion, 7, the ends of which are respectively connecte l, as bygluing or cementing, to in this instance an upper side of the tubularbell portion 1 and to a forward side of the throat portion 2. Arelatively thin longitudinal web or membrane or'the like 8 which may besubstantially rigid and vertical ifdesired may be arranged to form aconnection between the body portion 7 and an upper side of the tubularbell portion 1 and a forward side of the tubular throat portion 2. Anyimpulse traveling through solids such as compose the member 7 and theelement 2 may vibrate said web from opposite sides simultaneously. Thebody portion 7 and the web 8, when em loyed in the form shown, may servethe urther purpose of firmly uniting the said portions 1 and 2.

For sympathetic vibration or for rendering audible the sound waves froma suitable source, there may be provided a diaphragm or a supplementalor co-operative member having a thin wall or walls and comprising inthis instance a concave or bell member 9 of circular form, which has inthis instance an orifice or its open end facing in the same generaldirection as the tubular bell portion 1 and which has in this instanceits closed end pointed in a general direction toward the tubular throatportion 2. It is obvious the relative positions of the members named maybe varied. A method and means are being illustrated and the descriptionin general and the drawing'used in conjunction therewith are notintended for limiting purposes, but for making obvious and plain arevolutionary invention. The bell member 9 may be and, in the form shownis, preferably, connected to and supported by a sound conductingmember10,whichis pref- ..z; erably attached firmly to the said member 9and the said portion 1 adjacent the forward ends thereof. lVhensupported in this way, the wall of the member 9 will be at an angle to awall of the bell 1 and allow of sound reflection and sound interferencein the air space between said walls.

A plurality of suitably directed and, in this example, forwardlyconverging resonant members or bars or sound conduct- 1 ing members 11and 12, which may be com therein,'or to introduce a tuned straintherein, for purposes of controlling nodal lines or values, as shown inFig. 2.

It may as well be noted here that it is best to have the relativeproportions of the parts with which to effect selection of the frequencies desired in said resonator, or hell member, or the like. One of theadvantages of this arrangement of resonance is that it is applicable tovibrating systems in which the amplitude of the vibrating members is attimes quite small. The members 11 and 12 are preferably in associationand of like structure and of approximately equal length.

It is clear this acoustical device may employ a diaphragm in anysuitable manner and relative therewith a plurality of acousticallyscaled and balanced vibratory means, and the rate of frequency of any orevery part of the device, or a modification thereof, may be of computedphase relation relative with the frequency employed. As illustrated inFig.

3, the bell member 9 is, preferably, small in comparison with the mainamplifying or hell portion 1 but it may be of equal size or larger andits shape and form and acoustic surface resistance may be determined byexperiment.

All or desired parts of the walls of the tubular bell portion 1 and thetubular throat portion 2 being resonant and the walls of theco-operative bell member 9 being resilient or resonant and the membersor bars 11 and 12 being resilient or resonant and the sound conductingmembers or bars 3, 4 and 7 with their respective webs being resilient orresonant, sound vibrations will be transmitted from the throat portion 2to the tubular bell portion 1 and the co-operative bell member 9 by thesound conducting members or bars in a novel manner partly or largelyindependent as the case may be to the vibrations which pass directlythrough the air in the throat port-ion 2 and the bell portion 1. Bymeans of operable parts of this arrangement as shown, for example, aspecial result may be attained; or with certain combinations of theelements new over tones are delivered to the listener, the form of soundwaves is changed, the effective acoustic range of frequencies isincreased, and the amplified sounds coming from a suitable source areclearer and more natural than without the use of the different units orof the sound conducting members or bars and the co-operative bell member9, when one form of the device, for example, is used in connection witha sound-box of a talking machine reproducer or the like.

When an amplifier or acoustical apparatus constructed in accordance withone form of this invention is used for transmitting sounds to arecording medium, the sounds received at said medium are clearer, morenatural and of different wave form and period than would be the case ifthe sound conducting members or bars, were not used. The employment ofthe device therefore enables the production of a superior record.

While, in the scientific sense, sound is propagated like one ballhitting another, (a jarring process, I might say) I want it understood Ido not limit my invention by the use of the words or terms soundconducting member or sound conducting means or similar words or terms ofsimilar meaning.

In applying this invention the particular form to be used in any case togive the best results may be determined experimentally. The drawings arenot in scale and therefore are not to be taken as shop drawings. I haveproved by experimenting with this invention that a small periodic forceis continued long enough may set my resonant bars or boards or soundconducting members vibrating forcibly if the free .period of theresonant bars or boards or sound conducting members coincides or nearlycoincides with the period of the force. Equivalent substances of stressmay be employed instead of resonant substances Where foundinterchangeable in any part of the device,'or in any modificationthereof.

\Vhilea certain number of resonant members or sound conducting meansproduces a different result than by the employment of a less-number, Iwant it understood that I do not limit my invention to a certain numberof resonant members or sound conducting means, for the obvious reasonthat different people have different tastes for music and demanddiflerent tone qualities. I desire to connect the resonant bars ormembers or sound conducting members 3 L at forward points longitudinallyon the sound amplifier or sound apparatus, but I do not wish to limitmyself or invention to connections made only in that manner.

The length, width and thickness and the volume elasticity and density ofthe resonant members or sound conducting members 3, 4t and. 7, withtheir respective webs, and 11 and 12, have a direct relation to thedesired pitch of the tone and the volume of sound transmitted. In otherwords, the kind or sort of a member employed in construction, or in a indification thereof, effects the result obtained. Amplifiers forrecording and reproducing sound that are of different sizes and shapesandof different wall thicknesses may require one or more soundconducting members or resonant bars or members of different shapes,lengths, widths or anyone or more or thieknesses'or all fourdifferences, including differences in volume elasticity and density. Nordo I limit my invention to a sound conducting member or members or barsmade of wood any good stable substance that may conduct or influencesound, when connected properly, in an advantageous manner may be used.

I do not desire to be limited or restricted to any particular substanceemployed for the web or membrane 8 or the webs or. membranes 5 and 6, asany particular web or membrane may be of any suitable substance,

as the case requires. Nor do I desire to be l1m1ted to any particulars1ze or shape or elastimty, or the equivalent of elasticity, of

the web or membrane employed, for the mod" While I have shown only tworesonantmembers or bars or sound conducting members connected to avibratory body or tube or tothe tubular throat portion of the soundamplifier and connected to a diaphragm or to a co-operative resonatormember, yet I do not desire to limit my invention toa given number ofmembers or bars or sound conducting members so connected, for theobvious reason that the principle and method of transmitting soundvibration to or from vibratory bodies or to or from a sound amplifier orrecorder and to or from an aux,- iliary member or the like is hereinshown and described. Although different results are produced by a largernumber of resonant bars or member or sound conducting members connectedat places which may be predetermined on the sound amplifier, I do notwant the use of the word predetermined to limit this invention inanyway.

Nor do I limit or restrict this invention to resonant bars or membersthat are merely glued or cemented to asurface of an acoustical apparatusor sound amplifier. The resonant bars or members or sound conductingmembers may be fastened on as integral parts or otherwise, as may bedeemed expedient.

Nor do I want it understood that I limit my invention to a soundamplifier or sound recorder made of wood; any good resonant substanceformed integrally or otherwise may be used and with satisfactoryresults. I also wish it to be understood that the several features ofthis invention may be used either singly or collectively withoutdeparting from the scope of the claims.

I realize that many modifications of this invention are possible,therefore I say my in? vention is not limited to these particularconstructions shown and described and it is my intention to cover allother .modifications which may be made without departing from the spiritof my invention or the scope of the claims. y i s V That I claim as new,and desire to secure by Letters Patent of the United States, is, asfollows: 7

1. A sound amplifier comprising a tubular throat portion having resonantwall'sadapted to convey sound to or from a reproducing means, a smallsound resonator a distance apart, and suitable sound conducting meansamplifying member a distance apart, and a plurality of suitable resonantmembers con necting said resonant walls outwardly to said soundamplifying member.

3. A sound amplifier, or the like, comprising a tubular member havingresonant walls directly adapted to transmit sound to or from a soundsource, a co-operative bell member supported apart from said walls, andsound transmitting means firmly secured to a surface of said resonantwalls and firmly secured to said co-operative bell member.

4. In combination with a resonator, a supplemental amplifying member adistance apart provided with a single orifice said supplementalamplifying member having a plurality of sound conducting membersextending away therefrom.

5. A sound amplifier comprising a tubular throat portion and a tubularbell portion connected at adjacent ends and forming a curved passage forsounds, a supplemental amplifying member having comparatively thinwalls, said walls being resonant, and outward sound transmitting meansattached to said tubular throat portion on approximately opposite sidesthereof, said sound transmitting means being elevated bridge-likeapproximately side by side and connecting said supplemental amplifyingmember to said tubular throat portion.

6. In a sound amplifier provided with a tubular passage for sounds, saidtubularpassage having resonant walls provided with an inlet and anoutlet, a supplemental member having resonant walls, and elevated soundconducting means having predetermined lengths, widths and thicknesses tohelp regulate the pitch and volume of sound transmit ted to saidsupplemental member, and said sound conducting means firmly attached tosaid resonant walls of said tubular passage and having an elasticity anddensity similar in kind to the elasticity and density of said resonantwalls of said tubular passage.

7 In combination with a sound amplifier a supplemental member havingresonant walls and individual angular resonant bars of elevatedstructure, said bars being symmetrical and largely of uniform crosssection throughout their major lengths, said bars having tapered ends,each of said bars having a length, width, thickness, volume elasticityand density which may be predetermined to help regulate the pitch ofsounds passing through said amplifier and through said resonant bars,said resonant bars having a natural period of vibration adapted toharmonize with the natural period of vibration of said sound amplifierand adapted to increase the effective acoustic range thereof.

8. A sound amplifier comprising a tubular throat portion and a tubularresonator portion arranged to transmit sound from one to theother, saidtubular portions having resonant walls, and a resonant member having asubstantial body portion projecting away from said tubular portions, theends of said body portion being respectively connected a distance fromeach other to the walls of said tubular portions, and a thin webconnecting said body portion with the walls of said tubular portions,thereby to produce a different composition of the sound.

9. A sound amplifier comprising a tubular passage for sound, saidpassage having resonant walls, and a resonant member having asubstantial body portion in spaced away relation to said walls, saidmember having a given length to help regulate the pitch of soundtransmitted through said body portion, the ends of said body portionbeing respectively connected to the walls of said tubular passage, and athin web connecting said body portion with the walls of said tubularpassage thereby increasing the volume of sound by utilizing its energyin having sympathetic vibration in said body portion and in said web.

10. In an amplifying device, the combination with a tubular throatportion. of a resonator having thin walls, and a series of resonantsounding boards separated a slight distance from each other by thin websand arranged in substantially parallel planes, and means for connectingthe outer and inner ends of said boards securely, said boards beingsupported at one of their respective ends by said tubular throat portionand at the other of their respective ends by the said thin walls of saidresonator, and said series including outer boards long compared to innerboards in the series.

11. In a sound reproducing device adapted for introducing sympatheticvibration in a desired volume in a resonator having a closed end, amethod of controlling the vibratory effects delivered to said resonatorwhich consists in having elevated vibratory spaced means connected tosaid resonator relative to the natural frequency thereof and capable ofdelivering to said resonator frequencies of sound different thandirectly impressed at the opposite ends of said means and of having therelative proportions of the parts with which to effect selection of thefrequencies desired in said resonator.

12. A sound amplifier including a longitudinally curved resonant tubeand a separate bell member having resonant curved walls and a raisedresonant member extending from an exterior surface of said tube andconnected to said walls of said bell member to introduce a tuned straintherein.

13. In a sound amplifier like an acoustical apparatus for a talkingmachine or similar inventions, resonant walls forming a sound orificeresonator member supported beside said orifice, and a sidewisehomogeneous member extending from said walls to said CPI resonatormember, said sidewise homogeneous member being proportioned to influencesound impulses in said resonator member.

14. A sound amplifier having a resonant portion and an adjacent bellmember having resonant walls of determined natural frequency, and incombination therewith means for conducting sound impulses from saidresonant portion to said bell member, said means adapted to deliversounds of determined frequency relative to the frequency of the soundsprogressing through said resonant portion when in operation, the middleportions of said means being free to vibrate.

15. In combination in a sound device, a hollow body, webs, and resilientmembers, said members being secured to said hollow body, and at leastone of said members being secured to said webs.

16. In combination in a sound device, a resonator, and members havingwebs, said members being secured in spaced acoustic relation to saidresonator and to said webs.

17. A sound amplifier comprising a curved tubular body, and an outsideresonator, said tubular body having a portion connected transversely tosaid resonator, said tubular body and said resonator having walls ofresponse frequencies arrived at by comparison with what is necessary fora true simulation of the original sounds, said tubular body and saidresonator being acoustically a unit. 7

18. A sound amplifier comprising a tubular body adapted for directcommunication with a sound box, adjacent resonators connected to saidtubular body, one of said resonators being closed at one of its ends.

19. In a sound device, the combination with a bell member adapted to bein direct communication with a sound box, of a resonator exteriorlyadjacent said bell member and in secure connection therewith, saidresonator having one wall at an angle to a wall of said bell member, forpurposes of sound reflection and sound interference.

20. An acoustical apparatus consisting of spaced connected bell members,each of said bell members provided with means projecting therefrom foreffectively controlling at a plurality of points the frequency peakstherein. V

21. In an acoustical apparatus for a talking machine, a vibratorymember, and a thin circular resonant body concave from its center, soundtransmitting means between said member and said body and connected tosaid member, said means comprising a plurality of exterior raised spacedvibratory members of like structure and of approximately equal length,said means being secured to said body in a manner whereby resonancepeaks adjacent said center will be controlled.

22. In combination in a sound reproducing device, a resonant bodyhavingan orifice and a plurality of outside raised fairly elasticmembers connected to spaced apart places on said body, for purposes ofcontrolling reso nance peaks in said body, and the device as claimedadapted for response to vibratory impulses from a suitable source.

28. A sound amplifier comprising a hollow body, an elastic web securedthereto, said web having a structure shape and dimensions such that itis capable of responding with the exact amplitudes of sound desired ina. par

ticular instance, said hollow body being adapted to longitudinallyvibrate said web in the direction of the length of said hollow body,when the latter is vibrated by suitable means.

24. An acoustical device, comprising a body, an elastic web secured tosaid body, said web having a density elasticity and inertia directlyrelative with the associated structure and the use for which it isemployed and is thus adapted for responding with the particularfrequencies of sound desired, said body beingadapted to vibrate said webin the direction of its width by the sides of said web.

25. A sound amplifier for a reproducing device, comprising vibratorymembers that are essentially adapted for the transmission of desiredvibrations of sound, each of said tory means adapted to impart thenecessary I forced frequencies whereby said web will vibrate throughoutsubstantially as desired when in operation.

27. An acoustical device comprising a diaphragm and vibratory members ofcomputed phase relation when in connection therewith, said members beingattached to said diaphragm, whereby resonant peaks in said diaphragmwill be under finite control.

28. An alterable acoustic device comprising a diaphragm and a vibratorymember attached to an edge thereof, said member capable of being tunedrelative with the pos sible overtones that can be delivered by saiddiaphragm, for the purpose of obtaining the most complete range ofovertones thereby.

29. An acoustical device comprising a diaphragm and relative therewith aplurality of acoustically scaled and balanced vibratory means, saidmeans respectively connected by their ends to points on said diaphragmequidistant from each other, the necessary remaining acoustic factorsbeing taken into consideration in the construction of the device.

30. A sound amplifier for a reproducing device, comprising resonantelements of equal kind opposite each other and having an elastic web ofdetermined frequency therebetween, for purposes of vibrating said webfrom opposite sides simultaneously.

31. A sound amplifier comprising sound conducting means having a webconnected therebetween, said means being adapted to deliver vibratoryimpulses varying from each other, said means having structures adaptedto alter the vibratory impulses that can be delivered to said Web,substantially as set forth.

32. A sound amplifier comprising a tube, a web curved to follow thecontour of said tube, and a sound conveying member, said memberconnected to both said tube and said web and adapted to vibrate saidtube and said web under the influence of sound.

33. A sound amplifier adapted to be con nected to sound reproducingmeans and comprising a hollow body provided with a plurality of elasticwebs on opposite sides thereof and longitudinally thereof, said websbeing adapted to vibrate in sympathy with said hollow body, said webshaving periods of frequency needed for a full rendition of the tones andovertones prefigured in construction and accomplished by the use of thedev1ce.

34. An acoustic device comprising a dia phragm member adapted to befirmly held by a part thereof, and a vibratory member of computed stressattached to one point of said diaphragm, the members when in connectionbeing relative with the desired rate of frequency of said point of saiddiaphragm and relative with the computed potential and desiredfrequencies of said diaphragm and relative with various tested points onsaid diaphragm when at least one of these said tested points isacoustically connected with a source of sound.

35. An acoustical device comprising diaphragm means and interconnectedvibratory means adapted for free vibration, the latter means beingconnected with said diaphragm means in an opposed manner, saidinterconnected means being of alterable nature, and said diaphragm meansand said interconnected means having masses and forms of computed valuesone with another, so that the phase relations, one with another, ofdifferent parts of said diaphragm means are restricted when subject to agiven frequency and so that said diaphragm means shall vibrate in theexact manner required.

36. The method of introducing new frequencies from a source of sound ina diaphragm, which comprises contact means for transmitting a givenamount of vibration to said diaphragm, of having adjacent said means acomputed point of stress in said diaphragm dependent on an elementconnected therewith, and of having a computed mass of said diaphragmadapted to transmit a given amount of vibratory energy across said pointof stress and in computed phase relation therewith, and of having theseveral masses selected with regard for their acoustic structuralinterdependence and their collective ability to respond and react in agiven acoustic design.

In testimony whereof I have signed my name to this specification.

CHESTER ALFRED LINTON.

